Hi, the Figure 8 is generally for cases where there is no chance to reach the EUT with a 50 cm cable.
regards Ari Honkala >-----Original Message----- >From: [email protected] [mailto:[email protected]] On Behalf >Of ext Mike Hurley >Sent: 1. marraskuuta 2007 11:05 >To: [email protected]; [email protected] >Subject: RE: EFT Setup > >Hi Ted, Grace > >The only requirement on distance between the EFT generator and the >coupling clamp is a recommended maximum of 1m in Fig 6 (no minimum >specified). > >As regards distance between the clamp and the EUT, the standard states >in section 7.2.1 that 'when using the capacitive clamp, the minimum >distance between the coupling plates and all other conductive surfaces, >except the ground reference plane beneath the coupling clamp shall be >0.5m' so I believe the answer to Graces second question is yes. > >In relation to the 0.5m cable length specified, there appears to be a >contradiction in the standard as in Fig 8 for rack mounted equipment it >indicates a 1m cable length. Does anyone know the reason for this? > > >Mike Hurley > >Mead testing ltd >www.meadtest.com > > >-----Original Message----- >From: [email protected] [mailto:[email protected]] On Behalf Of >[email protected] >Sent: 30 October 2007 12:16 >To: [email protected] >Subject: Re: EFT Setup > >Hello Grace, > >I do not believe that there is a specific separation >requirement between >the EFT generator and the coupling clamp. I have a system from Keytek >that >came with a 0.5 m cable to connect the generator and the clamp. If >anything, I find supplied cable to be too short for my needs. >From what >I >know, the capacitive clamp should not cause interference with the EFT >generator even if they are in close proximity. > >The coupling clamp should not create significant radiated noise. In >this I >mean that the noise radiated by the clamp will be far less than that >coupled into the EUT through the cable under test. There should not be >a >significant problem with the test if the EUT is less than 0.5 >m from the >clamp as long as you have the 0.5 m length of exposed cable that is >specified. > >I will admit that I am not an expert in EMC measurements. I have been >working with susceptibility testing for about eight years, but >it only a >fraction of the work that I perform. I am posting my opinion >(and it is >only an opinion) because I have not yet seen a response to >your inquiry. >I >would like to encourage the more experienced EMC professionals >to let me >know if my though process is sound on this issue. If I am >wrong, let me >know; I am eager to learn more about the rationale behind the test >procedure. > >Ted Eckert >American Power Conversion/MGE >http://www.apc.com/ > >The items contained in this e-mail reflect the personal opinions of the >writer and are only provided for the assistance of the reader. The >writer >is not speaking in an official capacity for APC-MGE or Schneider >Electric. >The speaker does not represent APC-MGE's or Schneider Electric's >official >position on any matter. > > > > > "Grace Lin" > > <gracelinnj@gmail > > .com> >To > Sent by: [email protected] > > [email protected] >cc > > > >Subject > 10/29/2007 02:24 EFT Setup > > PM > > > > > > > > > > > > > > > >Dear Members, > >I have two questions and appreciate your inputs: > >1. Is there any clearance distance/requirement between an EFT generator >and >a capacitive coupling clamp (ccc)? > >2. Is there any clearance distance/requirement between EUT and a >capacitive >coupling clamp (CCC)? From Figure 1 of IEC 61000-4-4, the cable length >between the capacitive coupling clamp and the EUT "should be 0.5m +/- >0.05 >m". Does this mean the distance between EUT and CCC should also be >0.5m? > >We built a 4ft x 8ft table with the same size of metal sheet (reference >to >ground reference) on top of it. I would like to place an EFT >generator, >CCC, and EUT on top of the table. > >Thank you for your time and look forward to your help. > >Best regards, >Grace Lin >- ---------------------------------------------------------------- This >message is from the IEEE Product Safety Engineering Society emc-pstc >discussion list. 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Website: http://www.ieee-pses.org/ > >To post a message to the list, send your e-mail to [email protected] > >Instructions: http://listserv.ieee.org/request/user-guide.html > >List rules: http://www.ieee-pses.org/listrules.html > >For help, send mail to the list administrators: > > Scott Douglas [email protected] > Mike Cantwell [email protected] > >For policy questions, send mail to: > > Jim Bacher: [email protected] > David Heald: [email protected] > >All emc-pstc postings are archived and searchable on the web at: > > http://www.ieeecommunities.org/emc-pstc > - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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